Question

State the functions of the following in blood

a) Fibrinogen

b) Globulin

c) Neutrophils

d) Lymphocytes

Answer 1

Mechanism of blood clotting:

$\bullet$ During the process of blood clotting, thromboplastin is released from the injured tissue and from the disintegrated platelets. Thromboplastin combines with $C{a}^{++}$ ions to form the prothrombinase (enzyme). Prothrombinase inactivates heparin (anti- coagulant) and catalyses the breakdown of prothrombin into thrombin, which catalyses the conversion of fibrinogen into fibrin.

Fibrinogen:

$\bullet$ Fibrinogen is a protein present in the blood plasma and is formed in the liver.

$\bullet$ During clotting of blood, fibrinogen is converted into fibrin. This reaction is catalysed by thrombin.

$\bullet$ Fibrin forms a mesh over the wound where the corpuscles are trapped and forms a clot.

Globulin:

$\bullet$ Globulins are globular proteins found in blood plasma and are synthesized by the liver. There are different types of globulins which perform various functions.

$\bullet$ Some globulins act as enzymes, while some are antibodies.

Types of leucocytes:

$\bullet$ WBC’s (leucocytes) are of two types depending on the presence or absence of granules: Agranulocytes and Granulocytes.

$\bullet$ Lymphocytes and Monocytes are types of agranulocytes.

$\bullet$ Eosinophils, Basophils and Neutrophils are types of granulocytes.

Functions of neutrophils:

$\bullet$ Neutrophils are type of leucocytes which are attracted by the chemical released at the site of infection and being phagocytic they engulf the foreign matter, as a result their number increases during infection.

Lymphocytes:

$\bullet$ Lymphocytes are a type of Leucocytes (WBC’s). There are two types of lymphocytes B cells and T cells.

$\bullet$ The B cells take part in the immune responses by generating antibodies and the T cells take part in cytotoxic reactions where they destroy the infected cells.